The organizational structure of the proposed Clinical Trials Unit will comprise an Administrative Component and five Clinical Research Sites (Chatsworth, Umkomaas, Botha's Hill, Overport, Hlabisa) located in Durban, South Africa. The Administrative Component includes the CTU PI/Director, the CTU Co-PI/Deputy Director and two core staff groups; the Research Core and the Administrative Core. This Administrative Component will provide leadership to both stimulate and manage the Network research agenda, and ensure the highest scientific standards, ethical integrity and efficient fiscal and clinical operations within the CTU. The proposed Clinical Research Sites, staffed with highly competent teams, were selected based on available HIV/STI prevalence and incidence data, access to specific populations most affected by the HIV/AIDS epidemic, existing community partnerships, developed infrastructure, trained staff and established HIV prevention and treatment referral strategies for those identified as HIV positive at screening and those who seroconvert in prevention trials. These optimally configured Clinical Research Sites prominently positions the CTU to address the entire continuum of research needs within the HIV epidemic from prevention for HIV negative at-risk population, to treatment and care for HIV positive individuals. The CTU will have the flexibility and capability to conduct multiple studies at multiple Clinical Research Sites allowing for rapid response to the evolving epidemic, and ensuring optimal use of resources, both human and operational. Our research plan is to affiliate with both the HPTN and MTN Networks primarily due to our excellent track record in HIV prevention clinical trials. The Umkomaas, Overport and Botha's Hill Clinical Research Sites will participate in both Networks; while the Chatsworth and Hlabisa Clinical Research Sites will be dedicated to the MTN only. We intend to use a multidisciplinary approach to implement HIV prevention, treatment and behavioral research interventions, enhancing the CTUs ability to significantly contribute to addressing the HIV/AIDS epidemic locally, nationally and internationally. More importantly, we aim for research to benefit our communities by ensuring extensive community-wide HIV prevention education, home-based care/and lay counseling programs, at all Clinical Research Sites. ADMINISTRATIVE COMPONENT: